Mobile cranes require a counter ballast that can be installed at the superstructure. The counter ballast comprises a ballast carrier plate on which the required number of ballast plates can be stacked. To reduce the transport weight or the spatial dimension of the crane, the counter ballast, including the carrier plate, is removed from the superstructure of the crane for transport and is transported separately to the destination. At the destination, the counter ballast carrier plate can be installed at the superstructure by the crane itself or by means of an auxiliary crane. The counter ballast plate is first placed on the undercarriage of the crane for this purpose. It can be raised by means of the ballasting cylinders to the level of the installation points at the crane slewing platform of the superstructure and can be bolted there. However, the targeted placing of the ballast carrier plate on the undercarriage is a requirement for a smooth installation procedure.
Previous solutions provided one or more centering cones at the undercarriage that engage in corresponding recesses of the ballast carrier plate on a correct positioning. In addition, one or more metal abutment sheets were arranged at the undercarriage for a rough alignment of the counter ballast carrier plate.
It is, however, disadvantageous that the centering devices or abutments attached to the undercarriage construction may represent projecting edges during crane operation. This solution furthermore requires a large amount of complex welding work at the undercarriage.
It is therefore the object of the present disclosure to provide an improved and simpler solution for centering the counter ballast during the installation procedure.
Starting from the mobile work machine of the category, in particular a crane or mobile crane, a counter ballast carrier plate with one or more guide pins, with the latter being guidable along at least one guide edge of the undercarriage is provided. The counter ballast can be guided with the aid of the guide pins into a predefined installation position on the undercarriage by this mechanism during the unloading onto the undercarriage, for example by the crane itself or by any desired auxiliary crane, i.e. the counter ballast carrier plate is first raised to a height just above the undercarriage. In one embodiment, the ballast carrier plate may be raised to a height in the region behind the slewing platform, so that the guide pin or pins contact the at least one guide edge. In this position, the counter ballast carrier plate can be relocated, guided by the crane itself or by the auxiliary crane, into the predefined centered installation position. The ballast carrier plate is only completely placed onto the undercarriage on the reaching of the predefined installation position.
According to the present disclosure the ballasting may be done over the rear as a distinction from the prior ballast placement between the slewing ring center and the operator cabin.
The welding work at the undercarriage required in the prior art can be dispensed with by use of the one or more guide pins at the counter ballast carrier plate. Nor do any projecting edges arise at the undercarriage.
The arrangement of the at least one guide pin at a base plate of a ballasting cylinder of the counter ballast plate is particularly advantageous. If at least two guide pins are provided, they can be distributed over the base plates of the existing ballasting cylinders; ideally at least one guide pin is provided at a base plate per ballasting cylinder. In some embodiments, if an even number of guide pins are provided, they may be symmetrically arranged with respect to the longitudinal crane axis.
The at least one guide edge of the undercarriage may be formed by a matching push-in metal sheet of the undercarriage. A guide edge extending obliquely to the longitudinal axis of the crane has in particular proven advantageous. In one embodiment, in a configuration of the at least two guide edges for at least two guide pins, the guide edges may each run obliquely outwardly in the direction of the vehicle rear so that their spacing from one another increases toward the rear of the vehicle. In this case, the ballast carrier plate can first be guided along the guide edges until both guide pins contact their respective guide edge.
A movement of the counter ballast carrier plate transversely to the longitudinal direction of the crane can be blocked by the guide edge. Only degrees of freedom of the counter ballast carrier plate remain in a direction of the guide edge and in the vertical direction.
In another embodiment, the guide pin may be lockable in the predefined installation position. Once the installation position is reached, the ballast carrier plate may be completely placed on the undercarriage. The placing of the ballast plate may result in an automatic locking of the guide pin, in particular in that the latter engages into a recess of the undercarriage.
Only a vertical movement of the counter ballast carrier plate is enabled by this additional locking in the destination position; all other degrees of freedom are blocked. An accidental relocation of the counter ballast carrier plate may thereby be prevented. The vertical movement only allows a raising of the counter ballast carrier plate, in particular by means of the ballasting cylinders, into the installation position at the superstructure provided for this purpose.
In an additional embodiment, at least two guide edges at the undercarriage that run apart in the longitudinal or transverse crane direction and serve the guidance of two separate guide pins of the counter ballast carrier plate are provided.
In one embodiment, the at least one guide pin is movably supported in the vertical direction. The guide pin can, for example, be supported in a spring-loaded manner. A hydraulic and/or pneumatic actuation of the guide pine is also conceivable. The guide pin can furthermore be movable in the vertical direction by its own weight (gravitationally moveable). The movable support in the vertical direction provides that any damage to the undercarriage and/or to the guide pin can be avoided if the counter ballast carrier plate is placed incorrectly on the undercarriage. On too great a pressure load on the guide pin, the latter is, for example, displaced upwardly in the vertical direction. It is, for example, conceivable that the guide pin has a housing in which the guide pin may be vertically displaceably supported. On too great a pressure load on the guide pin, the latter moves into the housing.
In another embodiment, the at least one guide pin or the crane may be equipped with a visual and/or acoustic and/or electric display. This display possibility is intended to indicate an incorrect placement of the counter ballast carrier plate on the undercarriage to the crane operator. The display responds, for example, when the at least one guide pin is moved in the vertical direction and is in particular pushed partially or completely into the guide pin housing. Ideally, a corresponding visual display can be provided directly at the guide pin housing.
To compensate for any production tolerances or to finely adjust the desired centering position of the counter ballast carrier plate on the undercarriage, it is expedient if the at least one guide pin is adjustable in its position with respect to the counter ballast carrier plate by means of one or more setting means. A displaceable support transverse to its longitudinal axis is particularly preferred here. This is achieved, for example, by one or more metal adjustment sheets that can be actuated by means of screws and thus enable a displacement of the at least one guide pin or of the housing of the guide pin transversely to its longitudinal axis.
In addition to the crane in accordance with the invention, the present disclosure likewise comprises a counter ballast carrier plate having at least one guide pin for guiding the counter ballast carrier plate during the installation at a crane. The features of the counter ballast carrier plate may correspond to those features that have already been explained at the crane above with reference to the counter ballast carrier plate. This in particular relates to the movable support of the guide pin at the counter ballast carrier plate. To avoid repetition, a repeat description will be dispensed within the following.
Further advantages and properties of the present disclosure will be explained in more detail in the following with reference to an embodiment shown in the drawings.